AWS Adapters

Overview

The reventless-aws package provides AWS-specific implementations of the adapter interfaces defined in the core reventless framework. Adapters bridge the gap between Reventless's provider-agnostic components and AWS infrastructure services.

Reventless components are designed to be cloud-provider-agnostic. The reventless package defines abstract adapter interfaces, while reventless-aws implements these interfaces using AWS services like DynamoDB, SQS, SNS, S3, and Lambda.

AWS Service Mappings

Reventless components map to AWS services as follows:

Component	AWS Service	Purpose
EventLog	DynamoDB	Append-only event storage with partition key id and sort key sequenceNr
CommandTopic	SQS FIFO	Command message queues with FIFO ordering and deduplication
EventTopic	SNS / SNS FIFO	Event publishing with fan-out to multiple subscribers
QueryDb	DynamoDB	Read model storage with configurable indexes and TTL
EventCollector	DynamoDB Streams / SQS	Consumes events from EventLog or EventTopic
Task	S3	Stores task data; S3 events trigger Lambda on object create/delete
CommandGenerator	AppSync	GraphQL API for command generation with DynamoDB resolvers
Counter	DynamoDB Streams	Atomic counter updates triggered by DynamoDB stream events
ScheduledPublisher	CloudWatch Events	Time-based event publishing using CloudWatch Events rules
Heartbeat	CloudWatch Events	Periodic heartbeat signals using CloudWatch Events
Runtime	Lambda	Execution environment for all runtime operations

Adapter Details

The following AWS adapters are available. For how adapters are structured internally (deploy-time vs runtime, the make pattern, Pulumi.Output.t), see AWS Architecture.

Core Event Sourcing Adapters

• EventLog → DynamoDB - Append-only event storage with efficient replay
• DcbEventLog → DynamoDB - Tag-routed shared event store for DCB slices with per-tag consistency fences
• CommandTopic → SQS FIFO - Reliable command delivery with strict ordering
• EventTopic → SNS - Event publishing with fan-out to multiple subscribers
• EventCollector → SQS FIFO - Multi-source event collection from SNS and DynamoDB Streams

Data Storage Adapters

• QueryDb → DynamoDB - Read model storage with GSI support and AppSync integration
• Task → S3 - File-based task triggering with Lambda subscriptions

Supporting Adapters

• ScheduledPublisher → CloudWatch Events - Scheduled command execution
• Heartbeat → CloudWatch Events - Health check and keep-alive monitoring
• Counter → DynamoDB Streams - Atomic counting via change data capture
• StateTopic → DynamoDB Streams - State change publishing via DynamoDB Streams
• CommandGenerator → AppSync - GraphQL mutation resolvers for command generation
• QueryEngine → DynamoDB - Advanced query and scan operations

Folder Structure

reventless-aws/src/adapter/
├── AWS.res                     # AWS service constants and principals
├── AWS_Tags.res                # Tagging utilities
├── Adapter_Helpers.res         # Shared adapter utilities
├── Cloner/                     # Fargate-based data cloning
├── CommandGenerator/           # AppSync resolvers for commands
├── CommandTopic/               # SQS-based command channels
├── Counter/                    # DynamoDB Stream counter handlers
├── EventCollector/             # DynamoDB Stream / SQS event collection
├── EventLog/                   # DynamoDB event storage
├── EventTopic/                 # SNS event publishing
├── Heartbeat/                  # CloudWatch Events heartbeat
├── QueryDb/                    # DynamoDB read model storage
├── QueryEngine/                # DynamoDB query execution
├── Runtime/                    # Lambda runtime environment
├── ScheduledPublisher/         # CloudWatch Events scheduled publishing
├── StateTopic/                 # DynamoDB Stream state publishing
└── Task/                       # S3 task buckets